Stop motion for tight and loose warps



R. S. MARTIN STOP MOTION FOR TIGHT AND LOOSE WARPS Oct. 25, 1960 2Sheets-Sheet 1 Filed Dec. 9, 1958 INVENTOR: AYMOND S. MARTIN By ofilm,

ATTORNEYS Oct. 25, 1960 R. s. MARTIN 2,957,498

STOP MOTION FOR TIGHT AND LOOSE WARPS Filed Dec 9, 1958 2 Sheets-Sheet 2INVENTOR. RAYMQND 5. MARTIN ATTORNEYS United States Patent 2,957,498STOP MOTION FOR TIGHT AND LOOSE WARPS Raymond S. Martin, Fieldale, Va.,assignor to Fieldcrest Mills, Inc., Spray, N.C., a corporation ofDelaware Filed Dec. 9, 1958, Ser. No. 779,162 1 Claim. (Cl. 139358) Thisinvention relates to warp stop motions for pilefabric or terry loomsand, more especially, to an ill]!- proved apparatus for detectingabnormally slackened and/ or parted strands in the socalled loose warpor terry warp to effect operation of the stop motion and whereinoperation of the stop motion is not affected by predetermined slacknessintentionally induced in the terry warp.

As is well-known, the pile warp in terry and other pile-fabric looms isintermittently advanced relative to the ground Warp preceding each fastpick woven in at the fell of the cloth. Thus, the pile warp becomesslackened or loose relative to the ground warp and is taken up duringeach fast pick to form terry or pile loops. In order to actuate theusual plain loom stop motion, a drop wire rests upon each ground warpstrand and when one of the ground warp strands breaks or becomesexcessively slack, the respective drop wire falls into engagement with adetecting bar which actuates the loom stop motion.

Heretofore, drop wires have been used in a similar manner for detectingthe presence of broken or excessively slackened terry warp strands.However, apparatus had to operate in conjunction with the terry warplet-off or variable beat-up mechanism of the loom so as to support theterry warp drop wires independently of the terry warp strands duringeach loose pick and to thereby prevent false loom stoppage. Apparatus ofthis type is disclosed in US. Patent No. 2,065,731, for example. Suchsupporting apparatuses necessarily comprise considerable parts whichrequire space on the loom which is already overloaded with parts, andsuch apparatuses must be precise in their operation and are, therefore,expensive to manufacture, install and maintain? In order to overcome theabove and other defects, it is an object of this invention to provide anovel method and apparatus for detecting broken terry warp ends orabnormally slack terry warp strands for actuating the loom stop motionin which drop wires of relatively lightweight construction are supportedsolely by the terry warp strands and are maintained out of actuatingengagement with the detecting bar while they are supported only by thelatter strands even though predetermined slack is induced in thestrands. However, when the slack in any strand exceeds saidpredetermined amount or the strand is parted, the respective drop wireis dropped into actuating engagement with the detecting bar.

To this end, I have provided drop wires whose slotted upper portions areof such length that the upper walls of the slots will not drop intoactuating engagement with the detecting bar extending through said slotswhenever the terry warp is let off to a predetermined extent. Further, Ihave positioned separator bars in closely spaced relation to and astridethe drop wires so as to maintain the drop wires in upright position andto cause the terry warp strands to pass over a rear separator bar,downwardly between the rear and a succeeding separator bar, through thedrop wires, and then upwardly over the "forward or succeeding separatorbar in its course to the fell of the .cloth whenever slack is induced inthe terry ice warp. Thus, the terry strands are subjected to a minimumof stress as they move through the drop wires, since the steeper theslope of the strands, the lesser the stress applied thereto. This alsominimizes the resistance to movement of the strands through the dropwires.

Since the upper slotted portion of each terry warp drop wire isrelatively long to accommodate its range of vertical movement, it isanother object of this invention to provide an improved drop wire whoseupper portion, from its strand-contacting point or surface to its upperend, is heavier than its remaining or lower portion, the lower portionbeing of reduced length to minimize the over-all weight of. the dropwire.

Some of the objects of the invention having been stated, other objectswill appear as the description proceeds, when taken in connection withthe accompanying drawings, in which- Figure 1 is a somewhat schematicside elevation of a terry loom with which a preferred embodiment of myinvention is associated.

Figure 2 is a somewhat schematic View similar to the left-hand portionof Figure 1 showing a portion of a conventional stop motion actuatingapparatus as used on terry looms prior to my invention;

Figure 3 is a greatly enlarged view of the stop motion detectingapparatus shown in the central portion of Figure 1;

Figures 4 and 5 are isometric views of two types of separator anddetector bar support blocks shown in Figure 3.

In Figures 1 and'2, two terry looms or pile-fabric looms are partiallyillustrated, the loom of Figure 1 being equipped with a preferredembodiment of my improved stop motion actuating mechanism and the loomof Figure 2 showing, by way of comparison, a conventional type of stopmotion apparatus such as is disclosed in said US. Patent No. 2,065,731,for example. For purposes of brevity, pertinent parts of the loom shownin Figure 1 will be described and like parts of the loom shown in Figure2 will bear the same reference characters with the prime notation added,where applicable.

The loom of Figure 1 comprises a frame 10 and a lay L movable in theusual manner by a crank shaft 11. A reed 12 is pivoted, as at 13, to thelay and has wellknown operating connections, not shown, which areeifective periodically to change the angular relation of the reedrelative to the lay, the reed 12 and said connections being commonlyknown as a variable beat-up mechanism. This variable beat-up mechanismusually operates to move the reed 12 to forward position relative to thelay L with certain beat-up strokes of the lay, such as every third pickwhen producing a three-shot terry fabric. This periodic forward movementof the reed 12 is generally known as a fast pick.

Explaining the operation of the reed 12 further, the reed is somanipulated in a three-shot terry, for instance, as to have a shortforward motion on the first and second beats or picks of the cycle inorder to leave two shots of filling in different sheds an appreciabledistance. behind the fell of the cloth. On the third beat, however, thereed has a full or long forward stroke and beats the three shots offilling together with the terry warp up to the fell of the cloth, thuslooping the slack terry warp between the fell and the first of the threeshots of filling.

Strands of ground warp G are drawnfrom a ground warp beam 14 which maybe associated with any form of let-off, not shown, to produce the usualtension and hold the ground warp relatively tight at all times. A terryor pile warp beam 15 may be mounted on brackets,

"one of which is indicated at 16 in Figure 1. The terry 3 downwardlyfrom terry beam 15 to a terry warp let-E or feed mechanism generallydesignated at 17. Terry warp let-off 17 comprises front and back rolls20, 21 which are mounted for rotation on frame and are normally heldagainst each other. Terry warp T passes beneath roll 20, then over roll21, downwardly to a guide rod 22, and thence forwardly.

A ratchet feeding wheel 23 is secured to rear feed roll '21, and a feedpawl 24 is mounted on a rocking lever 25 which preferably oscillatesabout the axis of rear feed roll 21. Pawl 24 is controlled by a movablearm 26 which may be connected to a suitable operating means, such as apattern mechanism, not shown. In Figure 1, arm 26 is shown in loweredposition to permit pawl 24 to engage ratchet wheel 23 for rotating feedrolls 20, 21 in a step-by-step manner with oscillation of lever 25. Ofcourse, during the weaving of a heading, in which no terry loops are tobe formed, arm 26 is raised by the pattern mechanism so that the terrywarp T then remains taut during the weaving operation.

Rocking lever 25 is oscillated by means of a cam 30 mounted on a shaft31 carried by frame 10. Cam 30 is engaged by a follower 32 mounted onthe front end of a lever 33 oscillatably mounted on frame 10, as at 34,and having the lower end of a connecting rod 35 connected to its rearend. Cam 30 is shown in the form of an eccentric and is operativelyconnected to a gear, indicated diagrammatically at 36, rotating aboutshaft 31. Gear 36 is engaged by a gear 37 fixed on a driven main shaft40. Assuming that the loom is set up for weaving a three-shot terryfabric, gear 37 may be two-thirds as large as gear 36 so that connectingrod 35 is given an upward movement every third beat of the loom.

The lower or ground warp G is led upwardly from beam 14 over a guide bar41 and passes forwardly toward the warp stop motion control generallydesignated at 42. It will be noted that roll 22 is mounted on adjustablebrackets 44 so that roll 22 may be vertically adjusted and whereby theterry warp T extends forwardly and downwardly from roll 22 at an anglerelative to the substantially horizontal upper portion of the groundwarp G. The ground and terry warps G, T then extend forwardly from thestop motion control 42, through the usual harnesses or heddles 43 and toreed 12 where they are formed into pile or terry fabric generallydesignated at F. The terry fabric F may be taken up as it is Woven in awell-known manner at the front of the loom.

As is well-known, conventional stop motions or stop motion controls forterry and ground warps include banks of drop wires with the strands eachpassing through one of the drop wires and, upon parting of any one ofthe terry or ground warp strands, the corresponding drop wires dropdownwardly against detecting bars for actuating the stop motion.However, due to the fact that slack is induced in the terry warpperiodically, the terry warp drop wires have had to be supported bymeans other than the terry warp strands passing therethrough or thedetecting bars extending through the terry warp drop wires had to bemomentarily rendered ineffective in order that the dropping of the terrywarp drop Wires effected by induced slack in the terry warp strandswould not cause false stoppage of the loom. A device for supporting theterry warp drop wires during the fast picks; when slack is induced inthe terry warp strands, is disclosed in said US. Patent No. 2,065,731and an illustration of a. similar form of conventional device is shownin Figure 2 for the purpose of comparing a known type of terry warp stopmotion with that embodied in the present invention.

Referring to Figure 2, it will be noted that the strands of ground warpG extend through banks of drop wires A and the strands of terry warp Textend through front banks of drop wires B, there being one drop wirefor each strand in each instance. The drop wires A, B are all of thesame general conventional CQ 'l ction, each having a relatively heavy orsolid lower portion 45 and a slotted upper portion 46. A detecting bar47 extends through the slotted upper portions 46 of the drop wires A, Bin each bank and is adapted to be engaged by the upper wall of thecorresponding slot in any drop wire which is permitted to drop due tothe occurrence of excessive slack in any respective terry or ground warpstrand or upon any respective strands becoming broken or otherwiseparted. The terry and ground warps extend above separator bars or rods50 which are disposed adjacent opposite sides of each bank of drop wiresA, B to assist in retaining the drop wires in proper position as theterry and ground warp strands T, G are drawn through the drop wires.

Opposite ends of the detecting bars 47 and separator bars 50 aresuitably clamped or otherwise supported between series of support blocksonly one of the sets of support blocks being shown in Figure 2 indicatedat 52. Support blocks 52 are all mounted on a common threaded shaft 53having nuts 54 on opposite end portions thereof for clamping the blocks52 therebetween. The rear end of shaft 53 is curved downwardly and fixedin a bracket 55 carried by frame 10'.

As heretofore stated, the conventional terry warp stop motion includesmeans to support the terry warp drop wires when the terry warp is slack,and such means generally raises the terry warp drop wires slightly abovetheir normal position so that their weight is taken off the terry warp.To this end, a lifter plate 60 is positioned beneath the front pair ofbanks of drop wires B. Opposite ends of litter plate 60 are fixed tolevers 61, only one of which is shown, and these levers are operated bymeans, such as cam 30, so as to move upwardly and lift the two banks Bof terry warp drop wires at the same time that the slack is induced inthe terry warp T by the feed mechanism or let-off 17', thus preventingthe terry warp drop wires B from falling into engagement with therespective detecting bars 47 even though induced slack is present in theterry warp T. This also avoids placing undue stress on the terry warp Tas it is taken up with the succeeding fast pick of the loom. Since anexample of suitable apparatus for controlling and imparting movement tolevers 61 and lifting plate 60 is disclosed in US. Patent No. 2,065,731,a further description and illustration thereof is deemed unnecessary.Although the conventional type of terry warp stop motion illustrated inFigure 2 operates satisfactorily in some respects, it is apparent thatthe use of a plate such as plate 60 or a similar mechanism for raisingthe terry warp drop wires B requires considerable parts which are costlyto manufacture and which must be precise in their operation. Further,since the terry warp drop wires B of the conventional terry warp stopmotion control are supported during the forming of induced slack in theterry warp T, the parting or excessive slackness of any of the terrywarp strands is not detected during such intervals. Also, since cam 30is driven throughout operation of the loom, the lifting plate 60continues to operate for periodically raising and lowering the terrywarp drop wires B even during intervals in which terry loops are notbeing formed, such as during the weaving of the usual heading.

Now, there is shown in Figures 1, 3, 4 and 5 an improved terry warp stopmotion control for carrying out my improved method which stop motioncontrol obviates the necessity of providing apparatus of any kind forraising the terry warp drop wires while producing predetermined slack inthe terry warp T and which also enables detection of broken orabnormally slack terry warp strands at all times during operation of theloom regardless of whether or not the terry warp has induced slacktherein and without interfering with the taking up of the slack in theterry warp with fast picks in the forming of terry loops. Referring toFigures 1, 3, 4 and 5, the terry warp stop motion control 42 is alsoembodied in four banks of drop wires, including two banks of ground warpdrop wires C and two banks of terry warp drop wires D.

The ground warp drop wires C and associated detecting bars, separatorsand supports therefor may be of any desired or conventionalconstruction, such as the corresponding elements shown in Figure 2, thedetecting bars for the ground warp drop wires C each being designated at70 and the separator bars being designated at 71, 72 and 73. Thedetecting bars 70 are shown as being of a type used for controlling anelectrical stop motion. However, it is apparent that the features of myinvention apply equally well to any form of warp stop motion whichdepends for its operation upon the falling of a drop wire. In thisinstance, the separator bars 71, 72 are mounted in notches or slots 75provided in support blocks 76, which support blocks are also providedwith notches 77 in the upper portions thereof for supportingcorresponding ends of the detecting bars 70. As is conventional, blocks76 are mounted on a threaded shaft 80 having nuts 81 thereon forclamping the bar supporting blocks therebetween.

It will be observed in Figure 1 that each shaft 80, only one of which isshown, extends downwardly at its rear end and'is fixed in a bracket 82carried by the frame 10. As is usual, the. ground warp strands G passabove separator bars 71, 72, 73 and each passes through an eye oropening 84 in a medial portion of a respective drop wire C. In thisinstance, each drop wire C has a slot 85 in its upper portion throughwhich the corresponding detecting bar 70 loosely extends and, since thepresent stop motion control is shown as being of a' type used forcontrolling an electrical stop motion, opposed side walls of each slot85 in the upper portion of each conventional drop wire C are providedwith projections 86 which are adapted to engage insulatably separatedcontact elements 87, 88 of the respective contact bar 70 for closing acircuit therebetween whenever any one of the ground warp strands G isparted or becomes abnormally slackened to the extent that thecorresponding drop wire C will drop downwardly to where the projections86 will engage the contact elements 87, 88.

The terry Warp drop wires D are of construction similar to conventionaldrop wires (see U.S. Patent No. 2,556,332, for example) to the extentthat they are made from a relatively thin light metal and each includesa slotted upper portion 90 and a slotted lower portion 91 provided withrespective elongated slots 92, 93 therein.

The slot 93 is preferably open at its lower end and the upper wall ofslot 93 serves as a seat resting upon a respective terry Warp strand.Detector bar means, comprising detector bars 94 extend through the upperslots 92 in the respective banks of drop wires D and in this instance,the detector bars 94 are each in the form of an electrical contact baradapted to be engaged by the inclined upper wall 95 of a respective dropwire upon the latter being permitted to drop due to the presence ofabnormal or excessive slack in the respective terry warp yarns or due tothe breakage or parting of the respective terry warp yarn or strand.Each detector bar 94 is mounted in and insulated from a detector barholder 96 and each end of each detector bar holder 96 is positioned in anotch 97 provided in a respective detector bar support block 98 mountedon shaft 80.

Since the drop wires -D are of substantially lighter construction thanthe drop wires C, the contact or detector bars 94 are preferablyrelatively narrow with respect to the vertical. This also positions theupper edges of the bars 94 substantially below the level of the upperedges of the main contact or detector bars 70. Accordingly, the blocks98 are preferably reduced in height as best shown in Figures 3 and 5, ascompared to the main detector bar supports 76 shown in the left-handportion of Figure 3 and in Figure 4. The upper ends of the blocks 98 arenotched at 97 for receiving therebetween corresponding ends of detectingbars 94 and holders 96.

The lower portions of the detector bar support blocks 98 are alsorelatively thin horizontally at notches of slots 99, as compared to theconventional blocks 76, in order to support separator bars 100, 101 inrelatively closely spaced relationship and to also support separator bar100 in relatively closely spaced relation with respect to separator bar73. This provides a relatively narrow space through which the lowerportions 91 of terry warp drop wires D loosely extend. This not onlyassists in maintaining the drop wires D in substantially uprightposition, but also insures that the portions of terry yarn or terry Warpstrands, which are pulled downwardly into the space between adjacentseparator bars 73, 100 or 100, 101 by the respective drop wires D,extend at the steepestpossible angle from the points at which they arecontacted by the upper walls of the slots 93 to the upper edges of therespective separator bars. Thus, each time that terry warp T is let offor fed, drop wires D move downwardly and partially draw the terry Warpin which slack has been induced downwardly between adjacent separatorbars and, as the induced slack is subsequently removed from the terrywarp with the succeeding fast pick of the lay L and reed 12, drop wiresD otter a minimum of resistance to the movement of the terry warptherethrough and also apply very slight stress to the terry warp strandswhile they are being taken up with thefast pick. The angle at which theterry warp strands extend between roll 22 (Figure 1) and drop wires Dmay also be varied somewhat, through trial-and-error, to establish theoptimum angle at which the yarn will most readily pass through the terrywarp drop wires without being placed under excessive stress by verticaladjustment of the rod or roller 22, it being well-known that the steeperor more acute the angle of the yarn as it enters and leaves oppositesides of each drop wire, the more easily the yarn or terry strand passesthrough the slot 93 in the lower portion of each terry warp drop wire D.

Now, the important difference between the terry warp drop wires of thepresent invention and conventional drop wires lies in the fact that theupper wall 95 of slot 92 is disposed on a substantially higher levelrelative to the upper edge of the corresponding detector bar 94 andrelative to the level of the upper edges of the separator bars than isusually the case, in order to insure that, whenever predetermined slackis induced in the terry warp T, with consequent slackening of the terrywarp T at the drop wires D, the upper walls of slots 93 in drop wires Dremain in contact with and are solely supported by the strands of terrywarp.

It follows, therefore, that the drop wires D move downwardly to aconsiderable extent each time slack is induced in the terry warp T bythe feed mechanism 17. In spite of this, the upper walls 95 of the slots92 in the slotted upper portions of the terry warp drop wires D aremaintained above the level of or out of contact with the terry warpdetector bars 94. Also, in order that movement of the terry warp strandsthrough the terry warp wires D is not resisted due to constantengagement of drop wires therewith while the terry warp strands arecaused to form loops between adjacent separator bars, the additionalweight effected by providing the additional length to the upper portions90 of the terry warp drop Wires D is compensated for by reducing thelength of the lower portions 91 of the terry warp drop wires D so thatthe terry Warp drop wires D are actually top-heavy.

It is thus seen that I have provided a novel method and means forcontrolling a loom stop motion in which the upper walls or contact meansof the slots 92, through which the contact bars or detector bars extend,are maintained out of actuating position or out of contact with thedetector bars 94 while the terry motion drop wires D are supportedsolely upon the respective terry warps during both induced slack andtaut conditions of the terry warp and wherein, regardless of whether theslack is induced in the terry warp or the terry warp is under normaltension, upon the presence of abnormal or excessive slack in any one ormore of the terry warp yarns or upon the parting or breakage of any oneor more of the terry warp yarns, the respective drop wires D dropfurther to where the upper walls of the slots in the upper portionsthereof engage the respective detector bars for actuating the loom stopmotion, thus obviating the necessity of providing external means (otherthan the terry warp yarns) for maintaining the terry warp drop wires outof actuating engagement with the terry warp contact or detector barsduring the intervals in which the terry warp is let off or slackened bythe let-off or feed mechamsm.

In the drawings and specification there has been set forth a preferredembodiment of the invention and, although specific terms are employed,they are used in a generic and descriptive sense only and not forpurposes of limitation, the scope of the invention being defined in theclaim.

I claim:

In a terry loom having a terry warp and a ground warp, an oscillatablereed and means for intermittently letting ofl said terry warp to provideslack therein preceding successive fast picks of the reed whereby saidslack is taken up and terry loops are formed of the terry warp with eachfast pick, an improved warp stop motion comprising at least two firstand second banks of a plurality of drop wires, each of said drop wiresin the first bank resting upon and being solely supported by one of thestrands of said terry warp, each drop wire in said second bank restingupon one strand of said ground warp, each wire having a slot in itsupper portion, a first stationary detecting bar extending through theslots in the wires of said first bank, a second stationary detecting barextending through the slots in the wires of said second bank, the upperwall of each slot in the wires of said first bank being spacedsuiiiciently above the bar to remain out of contact with said bar eachtime said terry warp is slackened by said letting off means, and theupper Walls of the slots in said second bank of wires beingsubstantially closer to the second bar than are the upper walls of theslots in said first bank relative to said first bar whereby the upperwalls of the slots of said first bank will engage said first detectingbar only upon slack in respective strands of terry warp exceeding theamount of slack efiected in the terry warp by the letting off means orupon the respective strand of terry warp being parted, and whereby theupper portions of the walls of the slots of said second bank will engagesaid second detecting bar upon the occurrence of relatively little slackin respective strands of ground warp as compared to the amount of slackeffected in the terry warp by the letting off means.

References Cited in the file of this patent UNITED STATES PATENTS1,019,026 Cutting et al. Mar. 5, 1912 1,322,671 Davis Nov. 25, 19192,065,731 Payne Dec. 29, 1936 2,844,860 Ayars et a1. July 29, 1958FOREIGN PATENTS 557,294 Germany Aug. 20, 1932

